NullReferenceException: Object reference not set to an instance of an object
Devdog.InventoryPro.ItemCollectionBase.AddItem (Devdog.InventoryPro.InventoryItemBase item, System.Collections.Generic.ICollection`1[T] storedItems, System.Boolean repaint, System.Boolean fireEvents) (at Assets/Devdog/InventoryPro/Scripts/Collections/ItemCollectionBase.cs:1183)
Devdog.InventoryPro.VendorUI.AddItem (Devdog.InventoryPro.InventoryItemBase item, System.Collections.Generic.ICollection`1[T] storedItems, System.Boolean repaint, System.Boolean fireEvents) (at Assets/Devdog/InventoryPro/Scripts/Modules/Vendor/VendorUI.cs:232)
Devdog.InventoryPro.VendorTrigger.OnTriggerUsed (Devdog.General.Player player) (at Assets/Devdog/InventoryPro/Scripts/Modules/Triggers/VendorTrigger.cs:162)
Devdog.General.TriggerBase.NotifyTriggerUsed (Devdog.General.Player player) (at Assets/Devdog/General/Triggers/TriggerBase.cs:198)
Devdog.General.Trigger.DoUse (Devdog.General.Player player) (at Assets/Devdog/General/Triggers/Trigger.cs:152)
Devdog.General.Trigger.Use (Devdog.General.Player player) (at Assets/Devdog/General/Triggers/Trigger.cs:137)
Devdog.General.TriggerBase.Toggle (Devdog.General.Player player) (at Assets/Devdog/General/Triggers/TriggerBase.cs:90)
Devdog.General.TriggerBase.Toggle () (at Assets/Devdog/General/Triggers/TriggerBase.cs:80)
Devdog.General.TriggerInputHandlerBase.Use () (at Assets/Devdog/General/Triggers/TriggerInputHandlerBase.cs:58)
Devdog.General.TriggerInputHandler.OnPointerClick (UnityEngine.EventSystems.PointerEventData eventData) (at Assets/Devdog/General/Triggers/TriggerInputHandler.cs:84)
UnityEngine.EventSystems.ExecuteEvents.Execute (UnityEngine.EventSystems.IPointerClickHandler handler, UnityEngine.EventSystems.BaseEventData eventData) (at C:/buildslave/unity/build/Extensions/guisystem/UnityEngine.UI/EventSystem/ExecuteEvents.cs:50)
UnityEngine.EventSystems.ExecuteEvents.Execute[T] (UnityEngine.GameObject target, UnityEngine.EventSystems.BaseEventData eventData, UnityEngine.EventSystems.ExecuteEvents+EventFunction`1[T1] functor) (at C:/buildslave/unity/build/Extensions/guisystem/UnityEngine.UI/EventSystem/ExecuteEvents.cs:261)
UnityEngine.EventSystems.EventSystem:Update()